Illustrated herein are toner processes, and more specifically, aggregation and coalescence processes. More specifically, the present invention relates in embodiments to methods for the preparation of toner compositions by a chemical process, such as emulsion/aggregation/coalescence, wherein latex particles are aggregated with a wax and a crosslinked gel wherein the gel or crosslinking value is, for example, from about 20 to about 55 percent as measured gravimetrically; colorants, and a magnetite in the presence of a coagulant like a polymetal halide, or alternatively a mixture of coagulants or flocculating agents; thereafter stabilizing the aggregates with an organic complexing agent or a chelating agent, such as ethylenediaminetetraacetic acid (EDTA) dissolved in a base, such as sodium hydroxide, and thereafter coalescing or fusing by heating the mixture above the resin Tg to provide toner size particles which when developed by an electrographic process generates documents suitable for magnetic image character. In embodiments illustrated herein the chelating agent or compound allows the toner aggregates formed comprised, for example, of magnetite and metal coagulant ions like aluminum, for the formation of water soluble complexes which prevents or minimizes undesired interaction of magnetite or iron particles. The point of zero charge (Pzc) of magnetite and its relationship to pH and to temperature is illustrated, for example, in copending application U.S. Ser. No. 10/106,473, Publication No. 20030180648, the disclosure of which is totally incorporated herein by reference. By utilizing complexing or chelating compounds, the Pzc can be altered and thereby also minimize the generation of charges which may interfere in the toner emulsion aggregation process.
A number of advantages are associated with the present invention in embodiments thereof including, for example, excellent toner hot offset, for example above about 210° C., and more specifically, from about 210° C. to about 230° C.; a toner fusing latitude of from about 20° C. to about 40° C. wherein fusing latitude refers to a temperature in which, when a developed image is fused, evidences substantially no offset either to the substrate that the image is fused on, referred to as “Cold” offset or an offset on the fuser roll referred to as the “Hot” offset; a minimum fixing temperature of, for example, about 170° C. to about 195° C.; and extended photoreceptor life since the toner fusing temperature can be below about 195° C., such as from about 175° C. to about 190° C.; stable, controllable and substantially predictable PCZ, (point of zero charge), and wherein the charge on the magnetite particles can be either positive or negative depending, for example, on the pH of the medium, that is when the pH is acidic there results a positive charge; when the pH is basic there results negative charge, such as lowering the point of zero charge, for example from a value of 5.4 to about 3.5 of the complexed magnetite thereby enabling, for example, coalescence of the aggregates; and also in embodiments a process that enables a means of identifying how a toner was fabricated by, for example, analyzing for aluminum and organic complexing compound content.